AMHERST, MA, May 11, 2006 --/WORLD-WIRE/-- Researchers at the Political Economy Research Institute (PERI) at the University of Massachusetts today released the Toxic 100, an updated list of the top corporate air polluters.

"The Toxic 100 informs consumers and shareholders which large corporations release the most toxic pollutants into our air," says James K. Boyce, director of PERI's environment program. "We measure not just how many pounds of pollutants are released, but which are the most toxic and how many people are at risk. People have a right to know about toxic hazards to which they are exposed. Legislators need to understand the effects of pollution on their constituents."

The Toxic 100 index is based on air releases of hundreds of chemicals from industrial facilities across the United States. The rankings take into account not only the quantity of releases, but the relative toxicity of chemicals, nearby populations, and factors such as prevailing winds and height of smokestacks.

The Toxic 100 index identifies the top air polluters among corporations that appear in the "Fortune 500," "Forbes 500," and "Standard & Poor's 500" lists of the country's largest firms. The Toxic 100's top five companies are E.I. DuPont de Nemours & Co., US Steel, ConocoPhillips, GE, and Eastman Kodak.

A new feature of the web-based list is that readers can see the details behind each company, such as individual facilities owned by the corporation, specific chemicals they emit, their toxicities, and their contributions to the company's overall Toxic Score.

The data on chemical releases come from the U.S. Environmental Protection Agency's Toxics Release Inventory (TRI). The TRI is widely cited in press accounts that identify the top polluters in various localities. But reports based on these data alone have three limitations:

Raw TRI data are reported in total pounds of chemicals, without taking into account differences in toxicity. Pound-for-pound, some chemicals are up to ten million times more hazardous than others.

TRI data do not calculate the numbers of people affected by toxic releases--for example, the difference between facilities upwind from densely-populated urban areas and those located far from population centers.

TRI data are reported on a facility-by-facility basis, without combining plants owned by one corporation to get a picture of overall corporate performance.

The Toxic 100 index tackles all three problems. It includes toxicity weights and the number of people at risk using 2002 data-the most recent available from the EPA's Risk-Screening Environmental Indicators project. PERI researchers added up facility-by-facility data from the EPA to get corporate rankings.

"In making this information available, we are building on the achievements of the right-to-know movement," Boyce explains. "Our goal is to engender public participation in environmental decision-making, and to help residents translate the right to know into the right to clean air."